Caffeine is considered the most commonly used psychoactive drug in the world. Chemically, caffeine is 1,3,7 trimethylxanthine. It is usually absorbed by the gastrointestinal tract in 30-45 minutes depending on the persons rate of metabolism. Caffeine affects mood, stamina, gastric motility, and the cardiovascular system due to it's stimulant characteristics. Caffeine is a stimulant drug. If you find that you have a persistant desire for a caffeinated beverage you may be addicted.

The chemical mechanisms of caffeine addiction are similar to other addictions. It should be noted that experts do not agree that caffeine is addictive;however, many feel that it is highly addictive. The science of addictionology mainly is two pronged: physical and psychological. Because caffeine is a stimulant it raises heart rate when ingested. This rise in heart rate delivers more blood to the body and thus the person feels like they have more energy. Pleasure area's in the brain are stimulated by the ingestion of caffeine and a group of chemicals called endorphins are liberated into the bloodstream. These endorphins are the so called "pleasure chemicals" and the "natural painkillers" in the body. So this release of endorphins explains the chemical mechanism of caffeine addiction assuming you believe it is in fact addictive.